1. Field of the Invention
The invention relates to an anti-shake module, and more particularly to an adjustable anti-shake image-sensing module and a method for adjusting the same.
2. Description of the Related Art
In a conventional anti-shake digital camera, a floating image-sensing unit moves at a high speed on a plane perpendicular to an optical axis, suppressing or correcting a blurred image caused by shakes during a photographic operation, and thus achieving an anti-shake effect.
Referring to FIG. 1 and FIG. 2, JP2004056581A discloses an anti-shake image-sensing module 1 and an optical lens set A assembled therein for performing adjustment.
The anti-shake image-sensing module 1 comprises a base 11, a movable platform 12 disposed on the base 11, and an image-sensing unit 13 disposed on the movable platform 12. The optical lens assembly A is disposed on the base 11. The movable platform 12 can move on a plane perpendicular to an optical axis L and within a specific area B with a two-dimensional manner.
To obtain an optimal anti-shake effect, the movable platform 12 must be aligned with the base 11 prior to a photographic operation. Namely, the center C1 of the image-sensing unit 13 is aligned with the center C2 of the base 11, such that the movable platform 12 can provide an optimal effect for suppressing or correcting a blurred image.
Nevertheless, during assembly of the anti-shake image-sensing module 1, relative position errors are generated between constituent members (such as, magnets, Hall elements, driving coils, etc.) thereof, such that the center C1 of the image-sensing unit 13 deviates from the center C2 of the base 11, adversely affecting the anti-shake effect provided by the anti-shake image-sensing module 1.
Referring to FIG. 2 and FIG. 3, when the center C1 of the image-sensing unit 13 is moved onto the center C2 of the base 11, the position of the movable platform 12 needs to be adjusted by an external force. In JP2004056581A, an electronic signal is input to a coil (not shown) disposed on the movable platform 12 to adjust the relative position of the magnets (not shown) disposed on the base 11. When the center C1 of the image-sensing unit 13 is aligned with the center C2 of the base 11, the value of the input electronic signal is kept and stored in a memory of a digital camera.
Further, the movable platform 12 can originally move within the specific area B in a two-dimensional and symmetric manner. However, when the center C1 of the image-sensing unit 13 is aligned with the center C2 of the base 11, the specific area B within which the movable platform 12 can move becomes asymmetric, i.e. the distance by which the movable platform 12 can move in a certain direction is reduced.
Accordingly, the anti-shake image-sensing module 1 is not standardized when assembled. Specifically, the relative position of the movable platform 12 and base 11 is adjusted after a lens is completely assembled. Even though manufactured at the same time, multiple anti-shake image-sensing modules 1 are required to be adjusted one by one. Moreover, during adjustment, the value of the input electronic signal must be continually changed for trial and error and verified with an image determination technique. The results are then stored in the memory. Accordingly, the aforementioned adjusting process increases complexity of manufacturing the anti-shake image-sensing module 1. Additionally, adjustment results obtained from various digital cameras are often not the same, thereby increasing subsequent maintenance costs.
Additionally, after the adjustment, the asymmetric specific area B adversely affects the anti-shake effect provided by the anti-shake image-sensing module 1.